Sagas on Kafka

A travel site sells trips that combine a flight and a hotel. The flight service and the hotel service each own their own database, so no single transaction can reserve both. When the flight is reserved and the hotel then turns out to be full, the flight reservation must be canceled, or the customer pays for half a trip.

There are two common ways to coordinate those steps on Kafka. In the first, each service reacts to the events of the others, and no one is in charge. In the second, one orchestrator service sends each step a command and waits for its reply